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Hi NanoVNAuser
Yuo explanation is not very clear and picture a bit fuzzy. But iyt might be you need to introduce a delay via Display/Scale/Electrical delay
Kind regard
Kurt
-----Oprindelig meddelelse-----
Fra: [email protected] <[email protected]> P? vegne af nanovnauser@...
Sendt: 19. december 2019 10:11
Til: [email protected]
Emne: Re: [nanovna-users] Strange readings on my modded vna.

no ideas on this then folks?

I have to agree with this, I have a NanoVNA-F and I use it a lot more than the smaller model purely because I can see it. I would be happy to pay extra for a bigger display and as a consequence a bigger battery. I do not know how many units you need to sell and at what profit to make any project viable but a 3GHz VNA 5 inch display would be worth $180-200. I think that you can sell several hundred units at that price point.

People with disposable income in this hobby tend to be older and tend to have failing eyesight. A big display is very important.

Regards

Conrad PA5Y

________________________________
From: [email protected] <[email protected]> on behalf of Dr. David Kirkby, Kirkby Microwave Ltd via Groups.Io <drkirkby@...>
Sent: 17 December 2019 23:43
To: nanovna-users <[email protected]>
Subject: Re: [nanovna-users] First PCB pictures of the V2

On Tue, 17 Dec 2019 at 20:45, hwalker <herbwalker2476@...> wrote:

On Tue, Dec 17, 2019 at 10:40 AM, Dale Parfitt wrote:

Thank you Herb, So much traffic, I missed the specs.
====================================================

Dale,
I'd like to add a correction regarding the display size:

Gabriel indicated in her previous message that a working proto-type is
already available using a 3.2" ILI9341 display. A 4" ST7796S display is
being evaluated as an option by menu-driven switchover. Her team will
make a decision about whether to offer two versions for sale.

I would also like to add my voice to the many that would want to purchase
this with a larger screen.

How does the larger screen you may or may note use compare with the 4.3" on
the NanoVNA-F? The 4.3" of the -F is more attractive than 4" for obvious
reasons, but how about pixel count, and other technical features about the
screen.

I don't know if I'm unusual, but for me, the screen is more important than
the pure performance, as great performance is no use if you can't see the
blinking thing. Of course, if you are going to use it in a lab, with a PC
interface, the screen is pretty irrelevant. But there seem to be enough
people wanting a decent screen. The 6.5" on my iPhone XS max would be nice.
Ouch, that phone was ?1250, so it's not a fair comparison! But seriously,
size matters. ?????

Can you switch off the calibration and do a full range scan with nothing connected. This will show if there is a hw problem

--
NanoVNA Wiki: /g/nanovna-users/wiki/home
NanoVNA Files: /g/nanovna-users/files
Erik, PD0EK

Hi Bob,
a general point: Some (early?) firmware versions for the NanoVNA "only"
allowed operation up to 900 MHz. I suspect you have one of those - and that
you will need to upgrade your firmware in order to get it working in the
900-1500 MHz span.

In general: Upgrading to a newer firmware will probably also give you
higher accuracy, as some improvements were made to the way the measurements
were handled in the firmware. More knowledgeable list members can elaborate
on this, I'm sure.

--
Rune / 5Q5R

On Thu, 19 Dec 2019 at 03:16, Bob Albert via Groups.Io <bob91343=
[email protected]> wrote:

I have two nanoVNAs each with a different problem.

One refuses to accept any frequency above 900 MHz. I think I have had
that aspect working before but now am not so sure.

The other gives me a bad display on Smith chart, with the open circuit
near the middle rather than at the left. This one for sure worked fine
before.

Is there some kind of basic reset that can restore operation on the second
one, at least? The usual menu option RESET doesn't do it.

Hi Bob,

It is true that when one has several hours, one does not know the exact time.
Anyone with multiple VNAs doesn't know which one is accurate - maybe because everything is relative? :-) :-) :-)
(Although mass production works, there are still differences in the side-by-side product.)

73, Gyula HA3HZ

no ideas on this then folks?

Without display user define sweep points useful. Raw data also interesting or/and better calibration model on instrument. Currently no way to define precision oslt model on nanova. Many times coaxial line not easy compensate. Bluetooth or better wifi interface will be very useful. Display not required. Strong case with tab to support cord on mount + battery useful and two port. Output is sine wave or square wave?

YES IT IS HF,73

The firmware can be configured for up to 201 points, but there are still a few minor UI glitches we need to fix before this can be advertised. Sweep rate is by default 100 points/s, and this is what the plots shown above are taken at, but this can be adjusted in code to trade off noise vs speed. However V2 always shows new data in realtime as the sweep progresses (I'll maybe post a video if my internet speed allows) rather than a screen update every full sweep, so in practice it feels faster. There is a caveat though which is that the first sweep after changing frequency limits is always slower, because it has to do various internal corrections (see firmware code for details). In USB mode this means it's not advisable to do "segmented sweep", but there isn't a need because up to 1024 frequency points are supported in USB mode. This is all mainly capped by device RAM. Firmware is at:

#86": Two Notes On #86': UPGRADE : On the Results of Measuring Two-Ports
Using Only [NanoVNA] Channel [CH0] or a [LeastVNA]
16 December 2019 - /g/nanovna-users/message/8278

Note 1
At the paragraph (1) of the above, the "the usual form of { -1, 0, +1 }" must be
corrected and/or understood as follows:

"the usual form of { (-1, 0) , (0, 0) , (+1, 0) } ordered pairs of values in Cartesian
form"

in accordance with the remarks made at:

#73': On the sine qua non Core Uncertainty of AnyVNA - incl. NanoVNA - System
6 November 2019 - /g/nanovna-users/message/6529

Note 2
At paragraph (3) of the above -as well as in general- "The Common User" may
have a control on these matters, but only in the extent and depth that is permitted
by the manufacturer, who makes available any related information to him.

gin&pez@arg

:86"#

@Gary O'Neil, N3GO - 18 December 2019
/g/nanovna-users/message/8386

Dear Gary, Thank you for the interesting suggestions. We will prepare and
send you two copies - the one with colored underlined highlights. Best regards,
gin&pez@arg

How many sweep points? and how fast full-range single sweep?

It does appear that the cable is somehow involved.? Be all that as it may, my problems are not stopping me from getting good use out of the units.? I am repeatedly amazed at the accuracy and versatility it offers.? If careful I can make measurements to better than 1%.
The main lack for me is its inability to measure at audio frequencies.? No big deal; I have fancy gear for that.
I am tempted to buy a couple more just so I have redundancy big time.
Bob

Update.? I recalibrated and now the Smith display is okay.? Maybe I goofed and mixed up the calibration fixtures.
Both units have a problem where they turn themselves off without provocation.? Sometimes in the middle of a measurement.? One unit already has had the power control IC replaced.? Batteries are fine.
The one still won't go above 900 MHz.
Bob

I had your second problem when viewing the NANO on its screen while
connected to the PCwith the USB cable. Once I removed the USB cable, all
was as expected.

The first: I've never been able to get mine to go above 900 MHz, free
standing or connected to the PC with the USB cable.

Dave - W?LEV

On Thu, Dec 19, 2019 at 2:16 AM Bob Albert via Groups.Io <bob91343=
[email protected]> wrote:

I have two nanoVNAs each with a different problem.

One refuses to accept any frequency above 900 MHz. I think I have had
that aspect working before but now am not so sure.

The other gives me a bad display on Smith chart, with the open circuit
near the middle rather than at the left. This one for sure worked fine
before.

Is there some kind of basic reset that can restore operation on the second
one, at least? The usual menu option RESET doesn't do it.

--

*Dave - W?LEV*
*Just Let Darwin Work*
*Just Think*

I have two nanoVNAs each with a different problem.

One refuses to accept any frequency above 900 MHz. I think I have had that aspect working before but now am not so sure.

The other gives me a bad display on Smith chart, with the open circuit near the middle rather than at the left. This one for sure worked fine before.

Is there some kind of basic reset that can restore operation on the second one, at least? The usual menu option RESET doesn't do it.

well the antenna is my tv mast,total lenth about 45ft,its shunt fed thru a loading coil made from brake pipe tubing,the ground/counterpoise is all my copper plumbing,i live in a flat in a conservation area so imposible to do much antenna wise,its funny as with the current lash up my atu in the rig (kenwood ts-850 seems to match it on all the bands from 1.9mhZ thru to 10m.,would just be nice to measure it with the vna tho,i find it good for contacts 2000+miles but rubbish into g,i guess the take off angle is to low for the uk,dont know if i can alter it for nvis?,73.

Hi all,ive got strange readings on my modded vna,the mods are sma to bnc adapters on it,ive calibrated it with homebrew load and shorted termination and used a lenth of rg-58u cable with bnc fittings for the thru callibration,its fine from 130-450 mhz,its from 1-30mhz i get the strange readings,see pics,i assume its due to the capacitance of the sma to bnc adapters?,if so is there any way to compensate for this?,cheers in advance.

I presume this is for HF. A vertical antenna is not a differential
source/load and should not be fed with a balanced line - your 600-ohm
ladder line. A vertical of 1/4-wavelength long should be roughly 37 ohms
real. Even if you match it with a base loading coil, it is still
single-ended source/load and is appropriate for coaxial feed, NOT balanced
(differential) line. Eliminate the ladder line and the 9:1 transformer and
feed with coaxial cable.

Dave - W?LEV

--

*Dave - W?LEV*
*Just Let Darwin Work*
*Just Think*

well i was looking at the losses using coax,the ladder line is homebrew as i had a lot of enameled copper wire,thats why the 9-1 unun is by my tx,as then the atu matches it ok,whats the best way to conect to it then,just some crock clips on a short piece of coax from the vna connectors?,cheers in advance.